Lifting column for a medical examination table

ABSTRACT

An adjustable height support column for an examination table/chair is disclosed. The column includes nesting sleeve sections that are relatively slidable with respect to one another. The column uses camming guide rails in combination with cam followers located on the sleeve sections to provide for a column that is sturdy, compact, and may support a sufficiently heavy patient. One or more linear actuators provide for extension and retraction of the column.

BACKGROUND OF THE INVENTION

The present invention relates to medical examination tables and, morespecifically, to adjustable columns for examination tables.

Adjustable tables have been previously used in the medical fields.Generally, the focus of prior table adjustment has been for angular orrotational displacement of the table bed. That is, the table baseremains stationary while mechanical or hydraulic means tilt or angle thebed in other directions. Though these designs assist an examiner inrepositioning a patient for different procedures, they do not allow forvertical mobility of the table. For instance, if a patient were to bemoved from a wheelchair or a low resting gurney, such table would stillneed the patient to be lifted onto the table.

Previous inventions have contemplated adjustable bases. For instance,Schnelle et al. (U.S. Pat. No. 4,589,642), discloses an adjustable basethat uses hydraulic cylinders moving in opposite directions to adjustthe base height. However, the hydraulic operating unit is mounted on thetop of the cylinders, which increases the minimum height the cylindermay attain. Likewise, the placement of the unit provides for a louderoperating unit than desired. Also, though compact, the base does notprovide for the easiest access to all of the parts, if such partsrequire servicing. Thus, a compact, quiet, easily accessible base iscontemplated.

SUMMARY OF THE INVENTION

The present invention provides an adjustable column for an examinationtable that is compact, efficient, and may be easily serviced ifnecessary. The column is designed to minimize the space needed for thecolumn while still providing sufficient, sturdy support for a patientresting upon the examination table. Also, the column is designed so thatthe column height is adaptable over a wider range of heights thanpossible with the prior art. Likewise, the minimum height of the columnis less than previous minimum heights attainable by similar examinationtables of the prior art.

The column consists generally of three sleeve sections or members thatare telescopingly related to one another. The first sleeve section issecured to the base of the table, with the second sleeve sectionslidingly connected to the first sleeve section. A third sleeve sectionis slidingly connected to the second sleeve section and attached to thetable bed.

The three sleeve sections are designed so that each successive sleevesection nestingly fits around the previous sleeve section. Preferably,the first sleeve section has the smallest perimeter and the followingsleeve sections have increasingly larger perimeters. The sleeve sectionsform a generally rectangular shape, with the sleeve sections formed byjoining together two overlapping U-shaped sleeve sections of material.

The sleeve sections are moved upward and downward by a pair ofactuators, one located within the column sleeve sections and one locatedon the outside of the column sleeve sections. The inside actuatorcontrols movement of the second sleeve section with respect to the firstsleeve section. The outside actuator is attached at the bottom of thesecond sleeve section and the top of the third sleeve section so thatthe two sleeve sections may be moved simultaneously. The column may bedesigned having both the actuators located inside of the column, or bothactuators may be located outside of the column.

The sleeve sections of the column move relative to one another by guiderails and cam followers located on opposing sides of the column sleevesections. The guide rails are longitudinally extending with a pair ofoppositely disposed parallel guide surfaces. The guide rails are locatedbetween the first and second sleeve sections, and the second and thirdsleeve sections, with accompanying cam followers for each rail. Therails are mounted on the outside and inside of the second sleevesection, and the cam followers have an eccentric diameter for adjustmentagainst the rails. The cam followers are oppositely disposed and spacedapart and are in guiding contact with an oppositely respective disposedparallel guide surface of the guide rail. The design allows for smoothupward and downward movement of the column as well as support forheavier patients without diminishing the effectiveness of the column.

The design of the column allows easy access for maintenance, as well.Because the rail and cam followers inside the columns may be easilyaccessed through the top of the column without complicated disassemblyof the column, a person may service the column in a quick and efficientmanner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an examination table with the base in anextended position employing the present invention.

FIG. 2 is a perspective view of an examination table with the base in aretracted position employing the present invention.

FIG. 3 is a perspective view of the present invention in an extendedposition.

FIG. 4 is an overhead view of the present invention.

FIG. 5 is an overhead view of the present invention containing anactuator inside of the present invention.

FIG. 6 is a sleeve sectional perspective side view of the presentinvention showing the guide means of the present invention.

FIG. 7 is a close-up view of the guide means of the present invention.

FIG. 8 is a close-up sleeve sectional view of the body of the presentinvention.

FIG. 9 is a close-up perspective view of an actuator used in the presentinvention.

FIG. 10 is a cut-away perspective view of the view shown in FIG. 5.

FIG. 11 is a perspective view of an alternate column.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention which may be embodied inother specific structure. While the preferred embodiment has beendescribed, the details may be changed without departing from theinvention, which is defined by the claims.

FIG. 1 is a perspective view of an examination table 10. The tablegenerally comprises a support bracket 12, a support column 14, and abase 16. The focus of the present invention is on the support column 14and the adjustable nature of the column 14. The column 14 generallycomprises three sleeve sections or members: a first or lower sleevesection 18, a second or middle sleeve section 20, and a third or uppersleeve section 22. The first sleeve section 18 is attached to the base16, the second sleeve section 20 is attached to the first sleeve section18 and the third sleeve section 22, and the third sleeve section 22 isattached to the support bracket 12 of the table 10. The third sleevesection 22 may be attached to the support bracket 12 in any sufficientmanner that will secure the column 14 to the support bracket 12.

FIG. 2 shows the table 10 with support column 14 in a retractedposition. The third sleeve section 22 slides nestingly downward over thesecond sleeve section 20 (not shown), which slides nestingly downwardover the first sleeve section 18 (not shown). The height of the column14 may be adjusted significantly. As shown in FIG. 1, the table isextended to a height of about 42 inches, which is the typical or normalheight of an examination table. The present invention allows the column14 to be compressed to a minimum height less than 20 inches, orapproximately 19 inches, which facilitates transportation and movementof patients who may need to be moved from a wheelchair or othersimilarly shorter object. Previous designed prior art columns have beenknown to have a lowest height of only 22 inches, and a column range ofonly 18 inches. The three sleeve sections are arranged so that thediameters of the sleeve sections decrease from the third sleeve section22 to the first sleeve section 18, thereby preventing a sleeve sectionfrom interfering with the movement of an adjacent sleeve section.Similarly, the sleeve sections may be designed so that the diametersincrease as oppose to decrease from the third sleeve section 22 to thefirst sleeve section 18. Likewise it should be understood that theinvention is adaptable for use with more or fewer sleeve sections,depending on personal needs or preferences.

Referring to FIG. 3, a perspective view of the support column 14 isshown without an outer casing. A longitudinally extending guide rail orcamming guide rail 24 is attached to each of the surfaces 26 of thesecond sleeve section 20, preferably axially aligned with the center ofeach of the surfaces 26. The guide rail 24 is securely attached to thesecond sleeve section 20 and comprises guide means for movement of thecolumn 14. The guide rail 24 may be attached with any known means, suchas nuts and bolts, rivets, or screws, that will not interfere with thefunction of the guide rail 24. Preferably, each side of the secondsleeve section 20 has a rail 24 attached to each side, centrally alignedon each side. Such an arrangement provides for smooth movement of thecolumn 14 upwards and downwards and contributes to the stability of thecolumn 14.

FIG. 4 shows an overhead view of the column 14. The first sleeve section18 is shown nesting evenly within the second sleeve section 20, whichnests evenly within the third section 22. As mentioned above, the rails24 are located on the outside center of the surfaces or walls 26 of thesecond sleeve section 20. Also, a second set of rails 28 are located onthe inside center of the walls 26. The outside rails 24 and the insiderails 28 are manufactured and designed in the same way and performsimilar guide functions. The outside rails 28 guide the movement of thesecond sleeve section 20 with respect to the third sleeve section 22,and the inside rails 28 guide the movement of the second sleeve section20 with respect to the first sleeve section 18. To further assist theguide rails 24 and 28 in guiding the sleeve sections, a plurality of camfollowers 30 are situated along the rails 24 and 28. The interaction ofthe guide rails 24 and 28 and the cam followers 30 allow the sections tobe spaced apart in a generally uniform fashion. The actual function andmovement of the cam followers 30 will be described in more detail withrespect to FIGS. 6 and 8.

Still referring to FIG. 4, the first sleeve section 18 comprises aplurality of inwardly facing lips 32 corresponding to each side of thefirst sleeve section 18. The lips 32 allow the first sleeve section 18to be secured to a bracket 17, which will in turn be secured to the base16 (not shown). Any suitable means, such as screws, bolts, rivets, orother securing devices, may be used to secure the first sleeve section18 to the bracket 17 and, also, to the base 16. Likewise, instead oflips 32, other devices, such as braces or struts, may aid in attachingthe column 14 to the base. The first sleeve section 18 and the base 16could also be connected mechanically, by welding, with an adhesive, orwith any other suitable means.

FIG. 5 shows the same overhead view as shown in FIG. 4 except with theinclusion of an actuator 34 within the column 14 and a second actuator35 is attached to the outside of the column 14. The actuator 34 issecured to the bracket 17 by any fastening means as described aboveregarding the first sleeve section 18. The actuator 34 is arrangedwithin the column 14 in such a manner to minimize the amount of overallspace and area needed for the column 14. Also, the actuator 34 ispositioned so that it will not interfere with the movement of the sleevesections relative to one another.

Referring to FIG. 10, a perspective cut-away sectional view of theactuator 34 and the column 14 is shown. The bracket 17 is secured to thelips 32 of the first sleeve section 18, which is then secured to thebase 16. A second set of fasteners 19 is used to secure the first sleevesection 18 to the base 16 without any connection to the actuator 34 orthe bracket 17. It should be noted that the actuator 34 may be securedto the base 16 with the same fasteners that secure the first sleevesection 18 to the base 16, as described above with respect to FIG. 4,thereby minimizing the number of fasteners needed to secure the column14 to the base 16. However, such an arrangement would lead to anunstable column 14 if the actuator 34 were to be removed from the column14 for any purpose.

FIG. 6 shows a side view of the column 14. The guide rail 24 is showncentrally located on the second sleeve section 20 with the cam followers30 in contact with the guide rail 24. The cam followers 30 are shown inphantom as they are located on the inside surface of the third sleevesection 22. The guide rail 24 longitudinally extends the length of thesurface 26 of the second sleeve section 20. The guide rail 24 has a pairof oppositely disposed parallel guide surface 44, which provide an areafor the cam followers 30 to be in guiding contact with the guide rail24. The cam followers 30 are preferably placed parallel from one anotheracross the guide rail 24, with one of the cam followers 30 each incontact with one of the guide surfaces 44. A second set of the camfollowers 30 are spaced laterally from the first cam followers 30. Suchan arrangement provides stability and strength for the column to supportheavier patients, including patients up to at least 450 pounds (204kilograms), even if the patient is located in a cantilevered position onthe table. Such a cantilevered position may take place if a patient wereto kneel on an end of the table 10. The cam followers 30 are alsoarranged to rest only on the rails 24 or 28 and not the sleeve sections18, 20, or 22 of the column (see FIGS. 4 and 5), thereby lessening thestress of the parts of the column 14 as it moves upwardly anddownwardly. The actuator 35 is attached to the bottom of the secondsleeve section 20.

FIG. 7 shows the cam follower 30 in more detail. The cam follower 30 iscomprised of an inner rotating shaft 40 and an outer rolling sleevesection 42. The inner rotating shaft 40 will be secured to the columnsleeve sections 18 and 22 (see FIGS. 4 and 5) by a threaded section 43,while the outer rolling sleeve section 42 will make contact with therails 24 and 28 (See FIGS. 4, 5, and 6). The inner rotating shaft 40 iseccentric with the outer rolling sleeve section 42 to allow foralignment adjustment of the cam follower 30 against the rails 24 and 28.The outer rolling sleeve section 42 preferably, but not essentially, hasa slight crown (˜12 inch radius) to further align the cam followers 30with the rails 24 and 28. While the threaded section 43 is used toattach the cam followers 30 to the column 14, any suitable attachingmeans may be used, providing the outer section 42 is still allowed torotate. When the sleeve sections 18, 20, and 22 are moved relative toone another, the eccentric design of the cam follower 30 allows thesections 18, 20, and 22 to move in an axially aligned manner with oneanother. When traveling up and down the guide rails 24 and 28, the camfollower 30 design will allow for slight side-to-side movement to keepthe sections 18, 20, and 22 essentially aligned.

Now referring to FIG. 8, the design of the separate column sleevesections 18, 20 and 22 is discussed. The three sleeve sections, thoughhaving different dimensions are designed in the same manner. The holesfor the guide rails 24 and 28 and the cam followers 30 are not shown inthis Figure. A large U-shaped portion 36 and a small U-shaped portion 38are combined to form each of the respective sleeve sections. The twoportions 36 and 38 are secured together with conventional fasteners,such as nuts and bolts, to form a generally rectangular shape. Thesections 36 and 38 may also be combined by welding, adhesives, or othermeans that will allow the column 14 to keep its predetermined shape.Using different sized portions 36 and 38 prevents interference of thesecuring area to with the rails 24 and 28 and the cam followers 30 (seeFIGS. 4 and 5), and also makes it easier to accurately shape thesections.

Likewise, the column 14 could be designed to have more or fewer sectionsto make the sleeve sections, for instance the U sections 36 and 38divided each into two corner sections. The sleeve sections 18, 20, and22 should be interpreted broadly. Any nesting sections will fall withinthe scope of the sections described. Thus, the specific sections do nothave to be of a closed polygonal shape, but may have an open side oropen sides, providing that the specific section nests with the adjoiningsleeve section or sections.

As an example, FIG. 11 shows a perspective view of a differentembodiment of the first and second sleeve sections 18 and 20. The firstsleeve section 18 may be designed as a solid section with the secondsleeve section 20 surrounding it as a C-shaped. The rail 28 and camfollowers 30 (shown in phantom) would ride between the two sections 18and 20 in a similar fashion as previously described. Even though thesections are not enclosed polygonal shapes, they would fall within thescope of this invention as forming nesting sleeve sections.

A perspective view of the actuator 34 is shown in FIG. 9. The actuator34 is a linear actuator of a standard design known in the field ofinvention. The actuator 34 is comprised of three general parts: a piston46, a piston housing 48, and a motor 50. The preferred embodimentemploys two actuators 34 and 35, one actuator 34 located within sleevesections (see FIG. 5), and one 35 located outside of the sleeve sections(see FIG. 3). The inside actuator 34 and the outside actuators 35 are ofthe same design and perform the same general functions of raising andlowering the column 14. The outside actuator is attached to the bottomof the second sleeve section 20 and the top of the third sleeve section22 to allow both sections 20 and 22 to move at the same time. The insideactuator is attached to the bracket 17 at the same place where the firstsleeve section 18 is attached to the bracket 17 (see FIGS. 4 and 5). Theinside actuator controls relative movement of the second sleeve section20 to the first sleeve section 18. In FIG. 3, a third actuator, shown inphantom, is not considered part of the invention.

The column 14 will operate most efficiently if the rails 24 and 28 arealigned along the center of the surfaces 26 (see FIG. 4) and preferablyaligned with one another. The rails 24 and 28 are preferably made from ahardened to steel to prevent undue wear. Similarly, it is preferred thata rail and cam follower combination is present at each pair of facingsurfaces, but the column will operate if such an arrangement is notpresent.

The columns 14 are shown to be rectangular in shape. However, the sleevesections may be of any shape, provided that they having nesting surfacesso that the guide rails and the cam followers may interact. Also, thecolumns may not necessarily be of the same shape. For instance, a columnmay have an octagonal shape, while another may be rectangular, and thecolumn would still fall within the scope of the invention.

The guide rails 24 and 28 are shown as being attached or secured to thecolumn 14 sections. The term secured should be interpreted broadly toencompass any arrangement that will hold the guide rails 24 and 28relatively connected. For instance, the guide rails may be welded oradhered to the sections. Likewise, the guide rails may be integrallyformed as a section of one of the sections, which would still fallwithin the definition of secured as used in the specification. Provideda guide rail is connected to one of the sections in any fashion,integrally or separately, it will fall within the definition of securedas used herein.

The foregoing is considered as illustrative only of the principles ofthe invention. Furthermore, since numerous modifications and changeswill readily occur to those skilled in the art, it is not desired tolimit the invention to the exact construction and operation shown anddescribed. While the preferred embodiment has been described, thedetails may be changed without departing from the invention, which isdefined by the claims.

1. A camming mechanism for maintaining a predetermined spacing between apair of nesting, slidably relative sleeve members, said pair of sleevemembers including a first sleeve having an outer longitudinallyextending wall surface and a second sleeve member having an innerlongitudinally extending wall surface laterally spaced from said outerwall surface, said camming mechanism comprising: a longitudinallyextending guide rail secured to one of said sleeve members, said guiderail having oppositely disposed, parallel camming guide surfaces; and apair of oppositely disposed spaced apart cam followers, each of said camfollowers being in longitudinally guiding contact with a respective oneof said parallel cam surfaces.
 2. The camming mechanism according toclaim 1 wherein said cam followers are rotatably secured to the other ofsaid sleeve members.
 3. The camming mechanism according to claim 1further comprising a second pair of cam followers having at least one ofsaid second pair of cam followers in longitudinally guiding contact withsaid respective one of said parallel guide surfaces, said second pair ofcam followers longitudinally spaced apart from said first pair of camfollowers.
 4. The camming mechanism according to claim 1 wherein saidguide rail is axially aligned with said one of said sleeve members.
 5. Asupport column for an examination table having an adjustable height,said column comprising: at least two nesting sleeve sections, saidsleeve sections being slidable relative to one another; means formaintaining a predetermined spacing between an adjacent pair of saidnesting sleeve sections, said means comprising: at least onelongitudinally extending guide rail secured to one of said adjacentsleeve sections, said guide rail having oppositely disposed parallelguiding cam surfaces; at least one pair of oppositely disposed spacedapart cam followers being longitudinally in guiding contact with arespective one of said parallel cam surfaces, said cam followerssupported by the other of said adjacent sleeve sections; and means forsliding said sleeve sections relative to one another.
 6. The supportcolumn according to claim 5 wherein said each of said adjacent nestingsleeve sections includes surfaces, said surfaces facing surfaces of theother of said adjacent sleeve, said facing surfaces defining a polygonalspaced relationship, said facing surfaces supporting said spacing means.7. The column according to claim 6 wherein each of said nesting sleevesis rectangular in shape.
 8. The column according to claim 5 wherein saidsliding means comprises a linear actuator.
 9. The column according toclaim 5 further comprising a second pair of oppositely disposed spacedapart cam followers being in longitudinally guiding contact with arespective one of said parallel guide surfaces, said second pair of camfollowers latitudinally spaced apart from said first pair of camfollowers.
 10. An adjustable examination table comprising: a supporttable; a stationary base; and an adjustable height column, said columncomprising: a plurality of sleeve sections, said sleeve sectionsslidably, nestingly connected to one another, one of said sleevesections attached to said stationary base, another of said sleevesections attached to said support table; at least one longitudinallyextending guide rail secured to one of said sleeve sections, said guiderail having oppositely disposed parallel guide surfaces; at least onepair of oppositely disposed spaced apart cam followers beinglongitudinally in guiding contact with a respective one of said parallelguide surfaces; and means for sliding said sleeve sections relative toone another.
 11. The table according to claim 10 further comprising asecond pair of oppositely disposed spaced apart cam followers being inlongitudinally guiding contact with a respective one of said parallelguide surfaces, said second pair of cam followers latitudinally spacedapart from said first pair of cam followers, said second pair of camfollowers providing support for a patient on said support table.
 12. Thetable according to claim 11 providing up to at least 450 pounds supportfor said patient in a cantilevered position.
 13. The table according toclaim 10 wherein at least one of said guide rails is secured to one ofeach nesting pair of said sleeve sections, said cam followers arerotatably connected to other of said nesting pair of said sleevesections.
 14. The table according to claim 10 wherein said sliding meanscomprises at least one linear actuator.
 15. The table according to claim13 wherein said column further comprises a lower sleeve section, amiddle sleeve section, and an upper sleeve section, said lower sleevesection attached to said base, said upper sleeve section attached tosaid support table, and said middle sleeve section located between saidlower sleeve section and said upper sleeve section, said middle sleevesection having an inner wall and an outer wall, at least one of saidguide rails attached to said inner wall and at least one of said guiderails attached to said outer wall.
 16. The table according to claim 15wherein the height is adjustable within a range of at least more than 19inches.
 17. The table according to claim 16 wherein the height isadjustable within a range of at least about 23 inches.
 18. The tableaccording to claim 16 wherein the height is adjustable to a maximumheight of at least 39 inches and a minimum height of at least below 20inches.